at time of injury may be even lower than that at the time of assessment. In addition, if the time from last drink until the BAC measure was long enough such that the BAC reading was to fall to 0, the empirical relationship between self-reported volume and BAC would be biased downward. In each of these cases, the period over which the alcohol was consumed and the pattern of consumption can be key in the estimation of the gold standard BAC from that of the silver standard. In fact, due to their effect on BAC, these two factors are likely to be the largest contributors to the lack of agreement between self-report and BAC measures, much moreso than other factors such as demographics or typical drinking characteristics of the patient.
